I own a Nikon D60. I have two lenses, standard 18-55mm and 55-200mm. I am planning to buy a lens filter from ebay but I am getting confused about what size lens filter should I buy. 

If you take out the cap of the lens and see the backside - you will notice the size of the cap (I am guessing it is 58mm for both 18-55mm and 55-200mm).

As for which filter is better, I would say Hoya or B+W filters but these are expensive as well. You can find as low as 99 cents in ebay - which are from China (and you probably know why)

If you are new, you can as well look for polarized filters as well which are better for photos. I wouldn't be buying very expensive filters if I were just starting with entry level DSLR because you won't be able to differentiate the photo with filters and without one.

My Guess is 58mm too, I have Hoya it's decent for beginners!!

rockey07,
Like other friends suggested, you can see your lens to match exact size of filter. And if it's D60 kit lens 18-55 and 55-200 then it's 58mm diameter filter lens.

However if you feel to read something about it before buying it, I have spent little bit time writing about it and you can check this here http://www.umeshupreti.com/accessories/using-filters-in-digital-photography/

Happy Shooting!!!

Thanks guys for the info. UME$H bro!! your blog is really healpful. Thanks again.